There are six Minigames to unlock, which will appear on the left side of the map screen.
Effect - Code
Balloon Trip - Finish Dr Crygor's workout stage
Block Star - Finish Young Cricket's Microgames
Can Shooter - Finish Ashley's Microgames
Pyoro S - Play every microgame from every character
Tortoise & Hare - Finish Orbulon's Microgames
Tower Tennis - Finish Kat & Ana's Microgames